Two metal cylinders of a and b with radius 2.5 cm and 10 cm are arrange concentrically. The space between them ia filled with non moving coolant with conductivity (k)=20 W/m°c. The temperature of cylinder a and b are 120°c and 50°c respectively. Their length ia considered very long compared to their diameter. It is assumed that the heat transfer Takeshi place only to radial direction. Arrange the different way eq to find the temperature as a function of distance or T=f(r)!